Original article Isosweetness concentrations of sucrose and high-intensity sweeteners and antioxidant activity in white chocolate with functional properties Jana  ına Madruga Morais Ferreira, 1 * Bruna Marcacini Azevedo, 1 Fernanda Guimar~ aes Drummond e Silva, 1 Valdecir Luccas 2 & Helena Maria Andr e Bolini 1 1 Faculty of Food Engineering (FEA), University of Campinas (UNICAMP), Monteiro Lobato, 80, 13083-862 Campinas, SP, Brazil 2 Food Technology Institute (ITAL), Avenida Brazil, 2880, 13070-178, Campinas, SP, Brazil (Received 5 May 2016; Accepted in revised form 1 June 2016) Summary Healthier food products are an emerging trend in consumer demand. In this context, this study aimed at producing a prebiotic white chocolate with addition of an antioxidant source [goji berry (GB)] and replace- ment of sucrose by high-intensity sweeteners (sucralose and rebaudioside A). The ideal sucrose level in white chocolate was determined as 40.46% (w/w). Different concentrations of dried GB (3%, 6% and 9%, w/w) in white chocolate did not affect consumers’ preference. The isosweetness concentrations of the sweeteners were 0.05% for sucralose and from 0.10% to 0.16% (w/w) for rebaudioside A in prebiotic white chocolates. How- ever, among the prebiotic chocolates containing GB, sucralose was the best sucrose substitute. The prebiotic white chocolates with GB showed antioxidant activity up to three times higher than the samples without the dried fruit, determined by ferric reducing antioxidant power and oxygen radical absorbance capacity meth- ods. GB contributed to enhancing the nutritional value of white chocolate. Keywords Antioxidant activity, berries, chocolate, prebiotics, sensory analysis. Introduction Chocolate is one of the world’s most appreciated food, and this great success may be due to its flavour and pleasurable sensation (de Melo et al., 2007). Cho- colates are classified into dark, milk and white, according to the amount of cocoa, cocoa butter and milk in the formulations (Afoakwa, 2010). Liquor and cocoa powder are cocoa-derived products used in dark and milk chocolates. These products have bioac- tive properties correlated to the phenolic compounds with antioxidant activity, being associated with health benefits such as decreased blood pressure levels and modulation of immune function (Komes et al., 2013; Bordiga et al., 2015). White chocolate, unlike dark and milk chocolates, contains no liquor or cocoa powder and therefore has no antioxidant activity (Afoakwa, 2010). Goji berry (GB, Lycium barbarum) is a fruit known as a rich source of antioxidant compounds associated with health benefits by diminishing oxidative stress (Amagase & Farnsworth, 2011). Although it is traditionally cultivated in Asia, since the beginning of 21th century, it has been popular in Europe and America (Potterat, 2010). When added to white choco- late, GB can improve the nutritional value of this pro- duct due to its antioxidant potential. Recent study observed an increase in antioxidant activity of dark and milk chocolates containing cranberries and raisins (Komes et al., 2013). Nevertheless, the development of food products with natural ingredients containing nutritionally beneficial compounds is a trend in consumer market (Komes et al., 2013; Grigor et al., 2016); thus, the addition of a functional ingredient into white chocolate can bring health benefits and attract consumers. In this context, the addition of a prebiotic ingredi- ent into white chocolate is an alternative to make a functional chocolate. Prebiotics are considered functional food ingredients because they confer health benefits to the host associated with the improvement in gut microbiota balance, and these benefits include modulating gut function and transit time, improving immune system action and inhibiting precursor lesions of adenomas and carcinomas (Dominguez et al., 2014). *Correspondent: E-mail: janaina_mm@hotmail.com International Journal of Food Science and Technology 2016 doi:10.1111/ijfs.13190 © 2016 Institute of Food Science and Technology 1